# Copyright 2021 The Cirq Developers
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import annotations

from cirq import _import


def test_lazy_loader() -> None:
    linalg = _import.LazyLoader("linalg", globals(), "scipy.linalg")
    linalg.fun = 1  # type: ignore[attr-defined]
    assert linalg._module is None
    assert "linalg" not in linalg.__dict__

    linalg.det([[1]])

    assert linalg._module is not None
    assert globals()["linalg"] == linalg._module
    assert "fun" in linalg.__dict__
    assert "LinAlgError" in dir(linalg)
    assert linalg.fun == 1
